x/tools/cmd/gorename: keyword as identifier

[mengstr]

While refactoring some code written a bit too C-stylish with constants in uppercase I by mistake renamed a constant named SWITCH to switch. This particular operation was successful but the next rename failed.

I remember reading that gorename should take a well-typed program and either return an error or another well-typed program as its output. But in this case it broke the code for me by my own stupidity.

Would it be possible to have gorename check for reserved keywords before applying the requested changes?

package main
func main() {
    SWITCH := "X"
    _ = SWITCH
}

Renaming the variable SWITCH to lowercase and then trying to rename it to something else.

$ gorename -from 'main.go::SWITCH' -to switch
Renamed 2 occurrences in 1 file in 1 package.

$ gorename -from 'main.go::switch' -to toggleSwitch
/Users/matseng/gocode/src/github.com/smallroomlabs/bug1/main.go:4:9: expected operand, found ':=' (and 2 more errors)
gorename: couldn't load packages due to errors: github.com/smallroomlabs/bug1

[gopherbot]

CL https://golang.org/cl/25343 mentions this issue.